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i <br /> ASBESTOS by TEM 7402 <br /> FORMULA: Various MW: Various CAS: Various RTECS: Various <br /> METHOD: 7402 EVALUATION: PARTIAL issue 1: 15 May 1989 <br /> Issue 2: 15 August 1994 <br /> OSHA: 0.1 asbestos fibers >5 pm long)/cc; PROPERTIES: solid,fibrous,crystalline, <br /> 1 f/cc/30 min.excursion;carcinogen anistropic <br /> MSHA: 2 asbestos fibers/cc <br /> NIOSH: 0.1 f/cc(fibers>5 pm long)/400 L;carcinogen <br /> ACGIH: 0.2 crocidolite;0.5 amosite; 2 chrysotile <br /> i <br /> and other asbestos,fibers/cc;carcinogen <br /> SYNONYMS[CAS#]: actinolite[77536-66-4]or ferroactinolite[15669-07-5];amosite[12172-73-5];anthophyllite[77536-67-5j; <br /> chrysotile[12001-29-51;serpentine[18786-24-81;crocidolite[12001-28-4];tremolite[77536-68-61;amphibole asbestos[ 1332-21 4j. <br /> SAMPLING MEASUREMENT <br /> SAMPLER: FILTER TECHNIQUE: MICROSCOPY, TRANSMISSION <br /> (0.45- to 1.2-Um cellulose ester membrane.. ELECTRON(TEM) <br /> 25-mm diameter;conductive cassette) <br /> ANALYTE: asbestos fibers <br /> FLOW RATE: 0.5 to 16 Umin <br /> SAMPLE <br /> VOL-MIN*: 400 L @ 0.1 fiber/cc PREPARATION: modified Jaffe wick <br /> -MAX*: (step 4, sampling) <br /> `Adjust for 100 to 1300 fibers/mm' EQUIPMENT: transmission electron microscope;energy <br /> dispersive X-ray system(EDX)analyzer <br /> SHIPMENT: routine(pack to reduce shock) <br /> CALIBRATION: qualitative electron diffraction; calibration <br /> SAMPLE of TEM magnification and EDX system <br /> STABILITY: stable <br /> RANGE: 100 to 1300 fibers/mm2 filter area[1] <br /> BLANKS: 2 to 10 field blanks per set <br /> ESTIMATED LOD: 1 confirmed asbestos fiber above 95%of <br /> expected mean blank value <br /> ACCURACY <br /> PRECISION 0d: 0.28 when 65% of fibers are asbestos; <br /> RANGE STUDIED: '80 to 100 fibers counted 0.20 when adjusted fiber count is applied <br /> to PCM count[2j. <br /> BIAS: not determined <br /> RyyM8bL PRECISION Of): see EVALUATION OF <br /> ACCURACY: not determined <br /> APPLICABILITY: The quantitative working range is 0.04 to 0.5 fiber/cc for a 1000-L air sample. The LOD depends on sample <br /> volume and quantity of interfering dust, and is <0.01 fiber/cc for atmospheres free of interferences. This method is use d to <br /> determine asbestos fibers in the optically visible range and is intended to complement the results obtained by phase con trast <br /> microscopy(Method 7400). <br /> i <br /> i <br /> INTERFERENCES: Other amphibole particles that have aspect ratios greater than 30 and elemental Compositions similar to the <br /> asbestos minerals may interfere in the TEM analysis. Some non-amphibole minerals,.inay give electron diffraction patterns similar <br /> to amphiboles. High concentrations of background dust interfere with fiber identification. Some non-asbestos amphibole m inerals <br /> may give electron diffraction patterns similar to asbestos amphiboles. _ <br /> OTHER METHODS: This method is designed for use with Method 7400(phase contrast microscopy)- <br /> NIOSH Manual of Analytical Methods(NMAM),Fourth Edition,8/15/94 <br />